The present invention relates to a normal position detecting and latching mechanism of a functional component in a heating apparatus, such as a microwave oven, a microwave heating oven or the like.
As for most of microwave ovens, microwave heating ovens or the like, they have been configured such that functional members, for example, a turntable, a fan guard or the like are detachable for easy cleaning of the interior of a heating chamber. Accordingly, after having been washed, these functional members have to be placed back in their predetermined locations within the heating chamber. Consequently, there has been requested to install a certain mechanism for preventing such replacing from being failed forgetfully.
An example of such kinds of mechanisms according to the prior art is shown in FIGS. 6A and 6B of the accompanying drawings. This installed component detecting mechanism of the prior art, as shown in FIG. 6A, comprises a detective switch shaft 2 penetrating through an outer peripheral wall 1 of a heating chamber of a heating apparatus, and a limit switch 3 arranged outside the heating chamber so as to be located in a position facing to said detective switch shaft 2. When a specific functional member is not disposed inside the heating chamber 1, as shown in FIG. 6A, the detective switch shaft 2 is in a retracted position and thereby the limit switch 3 is in its inactivated condition, and, for example, such a caution may be given to indicate that the specified functional member is not installed in the predetermined location. As shown in FIG. 6B, when the functional member 4 is correctly installed in the heating chamber, said functional member 4 presses the detective switch shaft 2, which in turn brings the limit switch 3 to be actuated. Thereby, it can indicate that the specific functional member 4 is installed in the normal position.
Another example of such kinds of mechanisms according to the prior art is illustratively shown in FIG. 7. This conventional mechanism employs a proximity switch 5. The proximity switch generally has a detectable distance in a range of a few millimeters to some ten millimeters and is supposed to be used in an environment with a critical temperature of about 80xc2x0 C. to 120xc2x0 C. Based on above fact, in order to reduce the environmental temperature for the proximity switch and to make shorter a distance for detection, a recess 1A is formed in a portion of an outer peripheral wall 1 in a heating chamber, while a convex portion 6A is provided on a specified functional member 6, so that said convex portion 6A of the functional component 6 is allowed to fit into the recess 1A to bring the proximity switch to be actuated when the specific functional member is correctly installed in the heating chamber. That is, although the proximity switch 5 is located apart from the hole heating chamber in an operating environment with a temperature lower than the critical temperature, it still can detect whether there is the functional member or not within the detectable distance.
However, there have been the following problems with the conventional detecting mechanism described above with reference to FIG. 6. That is, since the detective switch shaft penetrates into the heating chamber, it is troublesome to clean the interior of the heating chamber. Further, because of a through hole, care must be taken upon washing with water. Dirt accumulation over the switch shaft 2 is likely to interfere with its driving and detective operation, resulting in a breakdown. Such an apparatus, for example, a microwave oven or a micro wave heating oven which performs a microwave heating needs preventive measures to be provided to the through hole to prevent the microwave leakage therethrough. Since the detective switch shaft 2 is in contact with the limit switch 3 during the heating apparatus is in use, the affection of heat transfer to the limit switch 3 via the functional member 4 within the heating chamber and the detective switch shaft 2 must be taken into account.
Further, there have also been the following problems with the conventional detecting mechanism described above with reference to FIG. 7. That is, forming the recess 1A in the outer peripheral wall of the heating chamber increase a man hour for manufacturing it, inevitably leading to the cost increase. If a concave or convex portion, such as the recess 1A is formed within the heating chamber wall, dirt is likely to accumulate therein or thereon and it is troublesome to clean it.
Accordingly, an object of the present invention is to provide a normal position detecting and latching mechanism of a functional component in a heating apparatus, which can solve the problems associated with the prior art as described above.
According to an aspect of the present invention, there is provided a normal position detecting mechanism of a functional component in a heating apparatus, comprising: a drive member mounted on said functional component side of said heating apparatus; a driven unit assembly mounted on a main body side of said heating apparatus; and a switch for generating a detection signal; said driven unit assembly comprising: a switch actuating member disposed in a back side of a flat wall surface of the main body side of said heating apparatus; a mounting bracket for operatively supporting said switch actuating member so as to be movable between said back side of the flat wall surface and said switch for generating the detection signal; and a bias member disposed between said mounting bracket and said switch actuating member, which applies a bias force for normally driving said switch actuating member against said switch for generating the detection signal; wherein said drive member is located in a position facing to said switch actuating member with said flat wall surface of said main body side of said heating apparatus sandwiched therebetween when said functional component is in its normal position in said heating apparatus, so that said drive member can provide a drive force to cause said switch actuating member to move in a direction away from said switch for generating the detection signal against the bias force of said bias member.
According to an embodiment of the present invention, said drive member is a magnet, and said switch actuating member is provided with another magnet having a different polarity from said magnet.
According to another embodiment of the present invention, said drive member is a magnet, and said switch actuating member is provided with an actuating iron core.
According to still another embodiment of the present invention, said switch for generating the detection signal is mounted on said mounting bracket.
According to another aspect of the present invention, there is provided a normal position detecting and latching mechanism of a functional component in a heating apparatus, comprising: a drive member mounted on said functional component side of said heating apparatus; a driven unit assembly mounted on a main body side of said heating apparatus; and a switch for generating a detection signal; said driven unit assembly comprising: a switch actuating member disposed in a back side of a flat wall surface of the main body side of said heating apparatus; a mounting bracket for operatively supporting said switch actuating member so as to be movable between said back side of the flat wall surface and said switch for generating the detection signal; and a bias member disposed between said mounting bracket and said switch actuating member, which applies a bias force for normally driving said switch actuating member against said switch for generating the detection signal; wherein said drive member is located in a position facing to said switch actuating member with said flat wall surface of said main body side of said heating apparatus sandwiched therebetween when said functional component is in its normal position in said heating apparatus, so that said drive member can provide a drive force to cause said switch actuating member to move in a direction away from said switch for generating the detection signal against the bias force of said bias member, as well as a latching force for bringing said functional component to be latched in said normal position.
According to one embodiment of the present invention, said drive member is a magnet, and said switch actuating member is provided with another magnet having a different polarity from said magnet, wherein a magnitude of magnetic force generated by both of said magnets is sufficient enough to provide a latching force so as to bring said functional component to be latched in the normal position by an attracting force generated between both magnets.
According to another embodiment of the present invention, said drive member is a magnet, and said switch actuating member is provided with an actuating iron core, wherein a magnitude of magnetic force generated by said magnet is sufficient enough to provide a latching force so as to bring said functional component to be latched in the normal position by an attracting force applied to said actuating iron core.
According to still another embodiment of the present invention, said switch for generating the detection signal is mounted on said mounting bracket.
According to still another embodiment of the present invention, said functional component is a door, and said switch for generating the detection signal serves as a door switch.